Brighter Days May Be Ahead: Continuous Measurement of Pediatric Intensive Care Unit Light and Sound

Abstract

Objective: To describe light and sound characteristics in the rooms of critically ill children. Design: Prospective observational cohort study, with continuously measured light and sound levels. Setting: Tertiary care pediatric intensive care unit (PICU), with a newly constructed expansion and an older, pre-existing section. Patients: Critically ill patients 0-18 years old, requiring respiratory or cardiovascular support. Patients with severe cognitive preconditions were excluded. Measurements and Main Results: One hundred patients were enrolled, totaling 602 patient-days. The twenty-four hour median illuminance was 16 (IQR 5-53) lux (lx). Daytime (07:00-21:00) median light level was 27 lx (IQR 13-82), compared with 4 lx (IQR 1-10) overnight (22:00-06:00). Peak light levels occurred midday between 11:00 and 14:00, with a median of 48 lx (IQR 24-119). Daytime median illuminance trended higher over the course of admission, whereas light levels overnight were consistent. Midday light levels were higher in newly constructed rooms: 78 lx (IQR 30-143) vs. 26 lx (IQR 20-40) in existing rooms. The twenty-four hour median equivalent sound level (LAeq) was 60 (IQR 55-64) decibels (dB). Median daytime LAeq was 62 dB (IQR 58-65) and 56 dB (IQR 52-61) overnight. On average, 35% of patients experienced at least one sound peak >80 dB every hour from 22:00 to 06:00. Overnight peaks, but not median sound levels nor daytime peaks, decreased over the course of admission. There was no difference in sound between new and pre-existing rooms. Conclusions: This study describes continuously measured light and sound in PICU rooms. Light levels were low even during daytime hours, while sound levels were consistently higher than World Health Organization hospital room recommendations of <35 dB. Given the relevance of light and sound to sleep/wake patterns, and evidence of post-intensive care syndromes, the clinical effects of light and sound on critically ill children should be further explored as potentially modifiable environmental factors.

Cognitive Dysfunction After Analgesia and Sedation: Out of the Operating Room and Into the Pediatric Intensive Care Unit

“…Multiple factors contribute to this sleep disruption, including non-modifiable factors, such as metabolic derangements of critical illness and necessary patient care interventions. However, modifiable factors are also an issue, including too little daytime light and orienting activity, excessive nighttime light and noise, patient care interventions that could safely be postponed, mode of mechanical ventilation, and the effect of medications including sedatives (Parthasarathy and Tobin, 2002;Al-Samsam and Cullen, 2005;Kudchadkar et al, 2014a,b;Greenfield et al, 2020).…”

Stuck in the Dark: No Association between Light, Sound, and Delirium in the PICU

“…16 Data on sound levels in the intensive care unit (ICU) demonstrate that individual patient rooms often reach levels four times greater than those recommended by the WHO. [17][18][19] No similar recommendations for light levels exist, although several studies suggest ICUs are dimly lit even during daytime hours, and there is little diurnal variation. 17,20 Therefore, it is important to evaluate the association between light and sound and the development of delirium, as these may be specific, modifiable factors.…”

Sleep disruption and delirium in critically ill children: Study protocol feasibility

“…Circadian rhythm dysregulation is one proposed cause of delirium (Maldonado, 2017), and sleep disruption is frequently observed in children with delirium (Holly et al, 2018). Children admitted to the PICU experience limited natural light exposure, excessive and unfamiliar sounds exposure, and frequent caregiving (Al‐Samsam & Cullen, 2005; Greenfield et al, 2020), as well as highly disrupted sleep (Kudchadkar et al, 2019). These environmental exposures and resulting sleep disruption can impair cognitive function (e.g., attention, working memory, emotional regulation; Kahn et al, 2013; Krause et al, 2017) and disrupt the circadian rhythm of melatonin release, which has antioxidant, anti‐inflammatory, and neuroprotective properties (Claustrat & Leston, 2015).…”

“…Although researchers have measured PICU light and sound exposure (Greenfield et al, 2020), sleep (Kudchadkar et al, 2019), and delirium (Gregory et al, 2021), these variables have not yet been fully explored in a single study. Furthermore, caregiving patterns have not often been included as a component of the PICU environment (Al‐Samsam & Cullen, 2005; Corser, 1996; Cureton‐Lane & Fontaine, 1997).…”

“…excessive and unfamiliar sounds exposure, and frequent caregiving (Al-Samsam & Cullen, 2005;Greenfield et al, 2020), as well as highly disrupted sleep (Kudchadkar et al, 2019). These environmental exposures and resulting sleep disruption can impair cognitive function (e.g., attention, working memory, emotional regulation; Kahn et al, 2013;Krause et al, 2017) and disrupt the circadian rhythm of melatonin release, which has antioxidant, antiinflammatory, and neuroprotective properties (Claustrat & Leston, 2015).…”